1. Field of the Invention
The invention relates to a device for detecting the position of a wheeled vehicle when it is driven into a vehicle treatment facility. In the sense of this invention, a vehicle treatment facility is understood to be especially a vehicle washing facility, e.g., in the form of a gantry washing facility or a drive-through car wash. However, vehicle treatment facilities can also be vehicle painting facilities, for example. In the sense of this invention, a wheeled vehicle is understood to be essentially an automobile with four wheels, of which, two wheels, one behind the other, run in the same track. However, wheeled vehicles can also be trailers or vehicles with four wheels in different tracks.
2. Prior Art
For the positioning of vehicles, especially automobiles, in front of a vehicle washing facility, there is often the problem that the driver of the vehicle to be washed does not drive the vehicle exactly in front of the entrance track of the washing facility. In a drive-through car wash, the wheels do not align with the guide, and in a gantry washing facility, the vehicle is laterally offset with respect to the center axis. This has the result that either the vehicle cannot enter in the washing facility or the gantry washing facility cannot function or it must be turned off during operation if the vehicle is laterally offset too far from the center. In addition, the vehicle can be offset not only laterally with respect to the center axis, but also diagonally in front of the automobile washing facility or in the gantry washing facility.
To assist the driver for positioning his vehicle in front of the drive-through washing facility or in the gantry washing facility, in addition to the well known wheel guidance disks and wheel reference tubes, a plurality of positioning or entry aids have also been envisioned. In the simplest case, for this purpose one or more mirrors in the field of view of the driver and directed onto the entry track are arranged in the vehicle treatment facility, as described in German Utility Model No. DE 299 12 916.0.
Furthermore, German Utility Model No. 298 09 426 shows an entry aid with a device for generating at least one optically visible guideline, which preferably runs in the center axis of the vehicle treatment facility and can be used by the driver for orientation.
In addition, a series of devices are also known from the prior art, which scan the contours of a vehicle either optically or based on ultrasound, in order to control the washing elements according to these contours. Here, examples are EP 0 283 446 A2, JP 10230821, JP 1001032, and JP 08207713. As far as these devices can optically detect the contours of the vehicle, this is preferably realized by means of light barriers or camera arrangements with subsequent image processing. All known devices are used merely to control the vehicle washing facility or the washing elements for vehicles that have been driven in, but they do not make it easier for the vehicle driver to position his vehicle correctly in the washing facility.
WO 00/50278 describes an operating method and a vehicle washing facility, which likewise provides a camera system, which optically detects the vehicle contours, and the acquired data is used in the control or regulation of system functions. In addition, this publication also uses the optical data, however, for controlling an entry aid. In this respect, the camera system is already active before the vehicle is located in its final treatment position and directional information or driving instructions are given to the driver by means of an optical display.
Although this camera arrangement offers considerable advantages relative to the prior art, it also has a few disadvantages. In particular, the vehicle approaching the system can be evaluated by optical means only by using very complicated and expensive image processing. In addition, the position of the vehicle front can be determined relatively reliably, but not a possible diagonal position of the vehicle in front of the treatment facility, which can be a result of imprudent or wrong steering maneuvers by the vehicle driver during entry. Such a diagonal position can be detected only very unreliably with all known optical sensors, whether light barriers or camera systems.
Finally, from the prior art a very simple electrical switching device for detecting the position of a single wheel of a vehicle in a washing facility is known, namely from JP 06321067. This describes a rotary plate to be driven over by the right front wheel of the vehicle to be washed. An electrical switch is connected to the shaft of this plate. Thus it can be ensured that the right front wheel will be located in at least a halfway correct washing position.
However, this publication also does not solve the problem of possible diagonal positioning. In addition, the rotary plate is used only for detecting the right longitudinal position of the vehicle and practically does not respond to a lateral offset, since, especially for vehicles with wide tires, the plate is practically always activated anyway when the longitudinal position asserts that the vehicle is not too far forward and not too far back.
Furthermore, electrical switching contact mats, which consists of a flat, flexible base material and band-shaped, pressure-sensitive switching elements distributed over the surface of the base material, are known from the prior art (cf., e.g., DE 198 01 052 C2). These switching contact mats were previously used for safety bars in order to stop, e.g., the movement of a gate when a vehicle was located in the gate region. Determination of position is not possible with these known switching contact mats.
Therefore, there is the problem of improving a device for detecting the position of a wheeled vehicle when it is driven into a vehicle treatment facility, so that lateral offset and diagonal positioning of the vehicle can also be reliably recognized.